In many circuit designs involving magnetics (e.g., transformers), magnetic flux fields generated external to the coupled magnetic medium (core) are present. Usually undesirable, these external fields are commonly referred to as “leakage,” and are sometimes confined or suppressed by shading bands or flux shields so deployed as to induce countervailing effects. However, the gapped magnetic medium generates a second and different form of external field because of the so-called “fringing effect.” This type of external field is not ordinarily subjected to suppression but may be redistributed or redirected. Coupled magnetic mediums with separate, shared, and gapped magnetic paths will generally exhibit a “fringing effect” imbalance between the coupled applied/induced magnetic medium paths, with attendant and inimical effects on operating parameters. For example, in a Single Ended Primary Inductance Converter (SEPIC) fed BUCK converter, values for parameters such as 2φ and LSFB (parasitic inductance) are greater when the converter is constructed using magnetics whose fringing effects are not compensated.